LONDON—The U.K. government's electronic surveillance policies came into the spotlight Tuesday at two separate public hearings.

Parliament debated fresh legislation that would require telecom companies to keep customer data for up to 12 months. Members of Parliament voted overwhelmingly 498 to 31 to approve the bill. The government has said it was important to fast-track new surveillance measures, called "Data Retention and Investigatory Powers," or DRIP, to ensure law enforcement and intelligence agencies don't lose...